Japanese submarine I-6 facts for kids
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|} The I-6 was a large submarine that served in the Imperial Japanese Navy. It started service in 1935. This submarine was a "J2 type," designed for long trips. It played a role in the Second Sino-Japanese War and World War II. During World War II, I-6 helped with the attack on Pearl Harbor. It also hit the American aircraft carrier USS Saratoga (CV-3) with a torpedo. The submarine searched for enemy ships in the Indian Ocean and South Pacific. It also took part in battles in the Aleutian Islands and New Guinea. The I-6 was sunk in June 1944.
Contents
- How I-6 Was Designed
- Building and Starting Service
- Early Service History (1935–1937)
- Service During the Second Sino-Japanese War
- Changes Before World War II (1938–1941)
- World War II Service
- First War Patrol: Pearl Harbor Support
- Second War Patrol: Indian Ocean
- Third War Patrol: Attacking Ships
- Fourth War Patrol: Aleutian Islands
- Supply Missions (1942–1943)
- Fifth War Patrol: Mines Off Australia
- New Guinea Supply Runs
- Later War Patrols (1943)
- New Guinea and Bismarck Archipelago (1943–1944)
| History | |
|---|---|
 Imperial Japanese Navy |
|
| Name | I-6 |
| Builder | Kawasaki Shipbuilding Corporation, Kobe, Japan |
| Laid down | 14 October 1932 |
| Launched | 31 March 1934 |
| Completed | 15 May 1935 |
| Commissioned | 15 May 1935 |
| Decommissioned | 15 December 1938 |
| Recommissioned | by 1 April 1939 |
| Fate | Sunk 16 June 1944 (see text) |
| Stricken | 10 September 1944 |
| General characteristics | |
| Class and type | J2 type submarine |
| Displacement |
|
| Length | 98.50 m (323 ft 2 in) |
| Beam | 9.06 m (29 ft 9 in) |
| Draft | 5.31 m (17 ft 5 in) |
| Depth | 7.58 m (24 ft 10 in) |
| Propulsion |
|
| Speed |
|
| Range |
|
| Test depth | 80 m (262 ft) |
| Boats & landing craft carried |
1 x Daihatsu (added August 1942–February 1943) |
| Complement | 80 officers and men |
| Armament |
|
| Aircraft carried | 1 x Yokosuka E6Y1 (until mid-1940) |
| Aviation facilities | Hangar, catapult (both removed mid-1940) |
How I-6 Was Designed
I-6 was the only submarine of its kind, known as the Junsen II or "J2" type. Before I-6, Japan built four Junsen I-type submarines. These were I-1, I-2, I-3, and I-4.
Then came I-5, a changed Junsen I type. It was special because it could carry a floatplane (a small airplane that lands on water). This was possible because it had a hangar, like a garage for the plane. I-6 was the next step in this design. It had both a hangar and a catapult to launch its floatplane. The last Junsen-type submarines, I-7 and I-8, also had a hangar and catapult for a floatplane.
Building and Starting Service
The I-6 was built by Kawasaki Shipbuilding Corporation in Kobe, Japan. Its construction began on October 14, 1932. The submarine was launched into the water on March 31, 1934. It was officially finished and started service on May 15, 1935.
Early Service History (1935–1937)
When I-6 first started service, it joined the Yokosuka Naval District. On June 1, 1935, it became part of Submarine Division 8. This division was in Submarine Squadron 1, which was part of the 1st Fleet. The 1st Fleet was a big part of the Combined Fleet.
On August 1, 1935, while doing practice drills near Ise Bay, I-6 crashed into the destroyer Akatsuki. The submarine's periscopes were damaged. It had to go to Yokosuka, Japan, for repairs. After repairs, it was directly assigned to the Yokosuka Naval District on November 15, 1935. In July 1936, I-6 carried a Watanabe E9W1 reconnaissance seaplane for testing. This plane was called "Slim" by the Allies.
On December 1, 1936, I-6 returned to its duties in Submarine Division 8. On March 27, 1937, it left Sasebo, Japan. It sailed with I-1, I-2, I-3, I-4, and I-5 for training. This training took place near Tsingtao, China. The six submarines finished their training cruise on April 6, 1937, arriving at Ariake Bay.
Service During the Second Sino-Japanese War
The Second Sino-Japanese War began on July 7, 1937. In September 1937, Submarine Squadron 1, including I-6, was moved. It joined the 3rd Fleet. This fleet was sent to Chinese waters to help the China Area Fleet.
The squadron, with I-1, I-2, I-3, I-4, I-5, and I-6, went to Hong Kong. They were joined by the submarine tenders Chōgei and Taigei. From Hong Kong, the submarines started operations. They helped Japan blockade China and patrolled China's coast. From August 20 to 23, 1937, all six submarines helped protect battleships. These battleships were carrying troops from Tadotsu, Japan, to Shanghai, China.
Submarine Squadron 1 stayed in Hong Kong until late 1938. To lower tensions with other countries, Japan pulled its submarines out of Chinese waters in December 1938.
Changes Before World War II (1938–1941)
I-6 remained part of Submarine Division 8. On December 15, 1938, it was put into a reserve status. Then, on April 1, 1939, it started working at the Torpedo School in Yokosuka. In mid-1940, the submarine's hangar and catapult were removed. After this, it could no longer carry aircraft. On November 15, 1940, Submarine Squadron 2, which included I-6, became part of the 6th Fleet.
By November 10, 1941, Submarine Division 8 included I-4, I-5, I-6, and I-7. I-7 was the squadron's main ship. The head of the 6th Fleet, Vice Admiral Mitsumi Shimizu, met with his submarine commanders. This meeting was on his flagship, the light cruiser Katori, in Saeki Bay. His chief of staff told them about the upcoming attack on Pearl Harbor. This attack would start World War II between Japan and the United States.
As the Japanese Navy prepared for the Pacific War, I-4, I-5, I-6, and I-7 left Yokosuka. They sailed for the Hawaiian Islands on November 16, 1941. On December 2, 1941, the submarines received a secret message. It meant that war with the Allies would begin on December 8, 1941, Japan time. This was December 7, 1941, in Hawaii.
World War II Service
First War Patrol: Pearl Harbor Support
On December 7, 1941, submarines from Submarine Squadron 2 took up positions. They spread out in the Pacific Ocean around Oahu. Their orders were to scout the area. They were also to attack any ships leaving Pearl Harbor during or after the attack. I-6 patrolled north of Molokai and Oahu.
On December 9, 1941, I-6 spotted the American aircraft carrier USS Enterprise (CV-6). It was sailing northeast with two heavy cruisers. I-6 tried to attack Enterprise but had to dive deep. Hours later, it sent a report. This led the Japanese to order nine submarines to try and find Enterprise. I-6 was then ordered to a new patrol area south of Oahu. Later in December, a crew member was hurt during a torpedo check. He died on December 27, 1941, and was buried at sea.
On January 9, 1942, another submarine, I-18, reported seeing an aircraft carrier. It was near Johnston Atoll. The 6th Fleet ordered submarines, including I-6, to form a line to find the carrier. I-6 replaced I-1, which had engine trouble. On January 10, 1942, I-6′s lookouts saw planes from the carrier five times. Its navigator used this to guess the carrier's location.
While on the surface on January 11, 1942, I-6 saw a U.S. Navy destroyer and submerged. Soon after, the aircraft carrier USS Saratoga (CV-3) appeared. It was sailing southeast with a heavy cruiser and another destroyer. I-6 fired three torpedoes at Saratoga. One hit the carrier on its port side. This killed six firemen and flooded three boiler rooms. Saratoga took on 1,100 tons of water and stopped moving. I-6 dove deep. The destroyers tried to find it but couldn't. I-6 reported hitting and likely sinking a carrier. Saratoga survived, but the damage kept it out of action for six months.
On January 12, 1942, I-6 left its patrol area for Kwajalein Atoll. It arrived on January 22, 1942, with very little fuel left. It left Kwajalein on January 24, 1942, for Yokosuka. It arrived there on February 2, 1942. In early February, it went into drydock for repairs.
Second War Patrol: Indian Ocean
While I-6 was in Yokosuka, Submarine Squadron 2 was assigned to the Dutch East Indies Invasion Force. This happened on February 8, 1942. On February 13, the staff of Submarine Division 8 moved from I-6 to I-4. I-6 left Yokosuka on February 14, 1942, heading for the Netherlands East Indies. It arrived at Staring Bay on Celebes on February 22, 1942.
On February 23, 1942, I-6 left with I-4 and I-5 for its second patrol. They went to the Indian Ocean west of Sumatra. On February 25, 1942, while on the surface, a Japanese Mitsubishi C5M plane spotted them. It was with nine Mitsubishi A6M Zero fighter planes. The Japanese planes thought I-6 and I-5 were enemy submarines. The Zeroes attacked, forcing I-6 to dive. It was not damaged. The rest of its patrol was quiet. It ended its patrol at Penang in Japanese-controlled British Malaya on March 8, 1942.
Third War Patrol: Attacking Ships
The Combined Fleet ordered all submarines of Submarine Squadron 2, except I-1, to scout. They were to check the coasts of Ceylon and western India. This was to prepare for Operation C, a big attack by aircraft carriers. So, I-6 left Penang on March 26, 1942, for its third patrol. Its area was in the Indian Ocean west of Bombay, India.
On March 31, 1942, I-6 saw an Allied steamer. It was about to fire torpedoes when it realized the ship was a hospital ship. It was likely the British hospital ship HMHS Vita. I-6 called off the attack. On April 2, 1942, I-6 was in the Arabian Sea southwest of Bombay. It spotted the British steamer Clan Ross. This ship was carrying cargo and explosives. I-6 fired two torpedoes, and one hit Clan Ross. The ship sank quickly, and 11 crew members died. I-6 surfaced and talked to the survivors. Its crew gave them water and biscuits and told them the direction to Bombay. They saluted the survivors and wished them well.
On April 7, 1942, I-6 met the British merchant ship Bahadur. It was carrying government supplies and ammunition. I-6 submerged and fired torpedoes, but Bahadur avoided them. I-6 fired more torpedoes from its stern, but they also missed. Then, I-6 surfaced and chased Bahadur, firing its deck gun. The gun jammed after one shot, and I-6 gave up. However, Bahadur suddenly stopped and lowered its lifeboats. I-6 got closer and fired two more torpedoes. Bahadur sank.
On April 10, 1942, I-6 surfaced southwest of Bombay. It attacked two small dhows with its deck gun, claiming both were sunk. Its patrol ended when it arrived at Seletar, Singapore, on April 17, 1942. It left Singapore on April 21, 1942, with I-5, heading for Yokosuka. It arrived on May 1, 1942, and had repairs until June 6, 1942.
Fourth War Patrol: Aleutian Islands
While I-6 was in Yokosuka, the Aleutian Islands campaign began. Japanese planes attacked Dutch Harbor, Alaska, on June 3–4, 1942. Then, Japan took over Attu and Kiska in the Aleutian Islands. On June 10, 1942, I-1, I-2, I-3, I-4, I-5, I-6, and I-7 were sent to the Northern Force for duty in the Aleutians. On June 17 or 20, 1942, I-6 left for the Aleutian waters for its fourth patrol. It joined the "K" patrol line near Unimak Pass. On July 7, 1942, it was ordered to move to the Kiska area. When the rest of Submarine Squadron 2 was ordered back to Japan, I-6 stayed behind at Kiska.
On July 29, 1942, a Japanese Kawanishi H6K flying boat reported an American seaplane tender at Natan Bay on Adak Island. I-6 went to check but found nothing. It was anchored off Kiska with other submarines when U.S. Navy ships attacked the island. This happened on August 7, 1942. All four submarines dove to avoid damage. Some chased the American ships, but none found them.
On August 15, 1942, I-6 was ordered back to Japan. It left Kiska the same day. While it was at sea, Submarine Squadron 2 and Submarine Division 8 were broken up. I-6 and I-5 were moved to Submarine Division 7. I-6 arrived at Yokosuka on August 23, 1942, and began repairs.
Supply Missions (1942–1943)
While I-6 was at Kiska, the Guadalcanal campaign began on August 7, 1942. American forces landed on Guadalcanal and other islands. As the fighting continued, Japan decided to use submarines to bring supplies to their troops on Guadalcanal. Submarines were fitted with a special mount on their decks. This allowed them to carry a waterproof Daihatsu-class landing craft. This boat could unload cargo along the coast. I-6 received a Daihatsu mount during its repairs. However, it was still in Japan when the Guadalcanal campaign ended on February 7, 1943.
After its repairs, I-6 left Yokosuka on February 16, 1943, carrying a Daihatsu. It arrived at Truk on February 23, 1943. On February 26, 1943, it unloaded its Daihatsu and took on fuel and supplies. It left Truk on February 28, 1943, for a test run.
Fifth War Patrol: Mines Off Australia
On March 2, 1943, I-6 left Truk for its fifth patrol. Its mission was to lay nine German-made magnetic mines off Brisbane, Australia. It was also to patrol the South Pacific off Australia's east coast. On March 8, 1943, Allied intelligence learned that I-6 had left.
By March 11, 1943, I-6 was northeast of Brisbane. It saw an Allied merchant ship and fired two torpedoes, but they missed. The ship didn't seem to notice the attack. On March 12, 1943, I-6 scouted Moreton Bay and Brisbane to find a good spot for its mines. On March 13, 1943, it laid all nine mines near the Australian coast. It used a device to launch the mines from its torpedo tubes. The mines were placed in what the captain thought was a shipping lane. I-6 then moved into the open ocean and sent a report. Allied intelligence intercepted the message. They learned a Japanese submarine had laid mines off Australia's east coast. But they didn't know the exact location.
The Royal Australian Air Force (RAAF) increased its patrols. I-6 had to stay submerged during the day because of the increased air activity. It patrolled quietly from March 14 to 16, 1943. On March 17, 1943, it saw Convoy BT-44. This convoy had two armed merchant ships, Charles C. Jones and Joseph Holt, escorted by the Australian minesweeper HMAS Gympie. I-6 fired two torpedoes at Charles C. Jones. The ships saw the torpedo trails and turned to avoid them. An RAAF plane also saw the trails and dropped a marker. Gympie and the plane searched for I-6, but it escaped. I-6 sent a report, which the Allies partly understood. Two U.S. Navy patrol ships searched for it but didn't find it.
On March 21, 1943, I-6 was ordered to go to Rabaul. It sent a report that evening, which the Allies partly understood. The Allies had sent three submarines to wait for I-6, but none saw it. I-6 arrived safely at Rabaul on March 27, 1943.
The mines I-6 laid were in an area rarely used by Allied ships. They were not noticed until March 24, 1943. The Australian ship HMAS Swan was doing gun practice there. As shells fell into the water, Swan saw two large explosions. At least two mines had exploded. Gympie arrived and started sweeping for mines. It found and detonated another mine. The mines were designed to rest on the seafloor and could move. The Allies found them in a slightly different spot than I-6 reported.
New Guinea Supply Runs
While I-6 was on patrol, a Japanese effort to bring supplies to New Guinea failed. Allied aircraft sank all eight ships and four destroyers in the Battle of the Bismarck Sea. Japan then decided to use submarines to carry supplies and troops to New Guinea. On March 29, 1943, I-6 was sent to the Southeast Area Fleet for supply runs to Lae in New Guinea.
It left Rabaul for its first supply run on April 3, 1943. It carried 30 passengers and 77 supply drums with weapons, clothing, and food. It arrived at Lae on April 5, 1943. There, it unloaded its cargo onto Daihatsus. It took on 29 passengers for Rabaul. Soon after leaving, it saw Allied motor torpedo boats. It dove quickly and avoided them, arriving safely at Rabaul on April 7, 1943.
I-6 visited Lae again on April 11, 1943. It unloaded 26 passengers and 77 supply drums. It then took 42 passengers back to Rabaul. On its third run, it visited Lae on April 17, 1943. It dropped off 28 passengers and 77 supply drums. After taking on 39 passengers, it left for Rabaul. It saw Allied motor torpedo boats near the Tami Islands but avoided them. While at Rabaul, it was reassigned on April 21, 1943. It was to support Japanese troops on Attu and Kiska in the Aleutian Islands.
I-6′s move to the North Pacific was delayed. It continued its supply runs between Rabaul and Lae. On its fourth run, it delivered 20 passengers and supplies on April 24, 1943. It left for Rabaul with 42 passengers. It visited Lae on its fifth run on April 30, 1943. It dropped off 30 passengers and supplies. It took 41 passengers and left. At dawn, it saw Allied motor torpedo boats and spent an hour avoiding them. It arrived safely at Rabaul. On its sixth run, it called at Lae on May 7, 1943. It delivered 10 passengers and 77 supply drums and picked up 12 passengers.
I-6′s seventh run was more exciting. It arrived at Lae on May 13, 1943. It unloaded 10 passengers and supplies. After taking four passengers, it started back to Rabaul. Soon after, U.S. Navy PT boats PT-150 and PT-152 saw I-6 on the surface. Each PT boat fired two torpedoes, but I-6 stopped, and they missed. PT-150 fired another torpedo, but the submarine sped up, and it missed. The PT boats then tried to get closer, but I-6 submerged. The PT boats stopped, and I-6 fired a torpedo at them. It passed under PT-150′s bow without exploding. I-6 continued to Rabaul. On May 14, 1943, it searched for airmen from Mitsubishi G4M bombers shot down. It rescued two aviators from the water near Buna, New Guinea.
On its eighth run, I-6 called at Lae on May 21, 1943. It delivered supplies and 31 passengers. It left for Rabaul with 40 passengers. On its ninth and final run, it visited Lae on May 28, 1943. It dropped off food, weapons, medicine, clothes, a Daihatsu, and 23 passengers. It did not take passengers back to Rabaul. Instead, it went straight to Truk. On May 31, 1943, it was reassigned to the 6th Fleet. It stopped at Truk from June 1 to 2, 1943. Then it went to Yokosuka, arriving on June 8, 1943, for repairs.
Later War Patrols (1943)
In the Aleutian Islands, Japanese troops on Attu were defeated by U.S. forces in the Battle of Attu. This happened between May 11 and 30, 1943. On May 21, 1943, Japan decided to evacuate its troops from Kiska. The evacuation began by submarine on May 26, 1943. Submarine Division 7 was sent to the 5th Fleet on July 1, 1943. On July 1 or 2, I-6 left Yokosuka for its sixth patrol. It went to Paramushiro in the Kuril Islands.
After stopping at Paramushiro, it helped with the Kiska evacuation. It patrolled with I-5 in the Bering Sea north of Kiska. Between July 17 and 19, 1943, the two submarines saw three U.S. destroyers three times. But they could not attack them. Japan finished the evacuation on July 28, 1943. I-6 ended its patrol at Paramushiro on August 4, 1943.
I-6 left Paramushiro on August 16, 1943, for its seventh patrol. Its area was off Kiska. The patrol was quiet. It returned to Paramushiro on September 3, 1943. It left again on September 5, 1943, and arrived at Yokosuka on September 10, 1943, for repairs.
New Guinea and Bismarck Archipelago (1943–1944)
On October 25, 1943, I-6 was sent back to the Southeast Area Fleet. It was to restart supply runs to New Guinea and the Bismarck Archipelago. On October 30, it left Yokosuka for Rabaul. From Rabaul, it began supply runs to Sio in New Guinea. It called at Sio on November 16 and December 4, 1943, without problems. But on its third visit on December 18, 1943, Allied aircraft attacked it while it was unloading. This forced it to leave before finishing, and it returned to Rabaul with some cargo. It visited Sio for the last time on December 27, 1943. Early that morning, after starting its return to Rabaul, it met Allied motor torpedo boats. They dropped depth charges. Later that day, Allied aircraft attacked it. It was not damaged in either attack. On the same day, it was ordered to find an Allied convoy. With only two torpedoes, it patrolled the Dampier Strait from December 28, 1943, to January 1, 1944, but did not find the ships.
On January 4, 1944, I-6 started new supply runs between Rabaul and Iboki, New Guinea. Its first two trips, from January 4 to 10 and January 17 to 21, involved delivering supplies. On its third run, leaving Rabaul on January 28, 1944, it carried only troops. It dropped them off at Iboki on January 30, 1944. It damaged its screws on an uncharted reef during this. It returned to Rabaul on February 1, 1944. On that day, Submarine Division 7 was directly attached to the 6th Fleet headquarters. Its next supply trip left Rabaul on February 3, 1944, to deliver supplies to Sarmi, New Guinea. On February 5, 1944, it was ordered to return to Yokosuka. It left Rabaul on February 13, 1944. It stopped at Lorengau on Manus Island on February 17, 1944. There, it delivered 12 heavy machine guns and ammunition. It then left for Yokosuka, arriving on February 29, 1944, for repairs.
The Loss of I-6
On June 15, 1944, the Marianas campaign began with the U.S. invasion of Saipan. The Japanese expected this invasion. On June 13, 1944, the commander of the 6th Fleet, Vice Admiral Takeo Takagi, ordered all available Japanese submarines to go east of the Mariana Islands. I-6, having just finished repairs, left Yokosuka for Saipan on June 16, 1944.
At 10:33 PM that evening, the Japanese cargo ship Toyokawa Maru saw I-6 surfacing near its convoy. The convoy was heading to Yokosuka. The Toyokawa Maru thought I-6 was an enemy submarine. It sounded an alarm and sharply turned towards I-6. It then rammed I-6 on its right side, just behind the conning tower. I-6 tilted heavily, flipped over, and sank a few minutes later. Toyokawa Maru then dropped depth charges and fired machine guns into the water where I-6 sank. None of I-6′s 104 crew members survived.
On July 1, 1944, the Japanese ordered I-6 to rescue Takagi and his staff from Saipan. But I-6 did not respond. The Japanese then declared it missing. The 6th Fleet tried one last time to contact it on July 3, 1944.
Some other stories about I-6′s loss exist. One says Toyokawa Maru sank it off Saipan on June 30, 1944. Another says the American ships USS William C. Miller (DE-259) and USS Gilmer (APD-11) sank it west of Tinian on July 19, 1944.
I-6 was officially removed from the Navy list on September 10, 1944.
